Non-planar ball rebound wall

ABSTRACT

A wall structure for practicing tennis or similar games. The structure provides a rebound surface which is non-planar so that rebound characteristics are obtained which differ from those of a conventional flat practice wall. In particular the rebound surface defines a generally concave configuration coupled with indented or projecting formations so that generally a ball rebounds towards a center line of the wall but an unexpected bounce is obtained when the ball strikes a formation.

United States Patent McDougall [5 4] NON-PLANAR BALL REBOUND WALL [72]Inventor: Julia P. McDougall, Transvaal,

Republic of South Africa [73] Assignee: 'h'anly Walls and Mini Courts(Proprietary) Limited, Johannesburg, Transval, Republic of Sou h A a 221Filed: Sept. 9, 1969 [21] Appl. No.: 856,292

[30] Foreign Application Priority Data Sept. 18, 1968 South Africa..68/6047 June 27, 1969 South Africa ..69/4579 [52] US. Cl. ..273/29 A,273/26 A, 273/DIG. 7, 273/DIG. 8 [51] Int. Cl. ..A63b 61/00 [58] Fieldof Search.....273/26 R, 26 A, 127 R, 29 R, 273/29 A, 30, 102.4, 127 C, lR, DIG. 8

[56] References Cited UNITED STATES PATENTS 1,51 1,430 10/1924 Schonberg..273/26 A 1,623,284 4/1927 Stoddart ..273/ 127 R 3,001,790 9/ 1961Pratt ..273/26 A 3,088,735 5/ 1963 Clark ..273/30 3,101,198 8/1963Williams ..273/l02.4 X 3,045,400 8/1964 Yoakum ..273/DlG. 8

[4 1 Oct. 10, 1972 3,456,945 7/1969 Epply ..273/1 R 3,384,372 5/1968Dickens ..273/55 FOREIGN PATENTs OR APPLICATIONS 395,830 1/1966Switzerland ..273/29 R 733,543 10/1932 France ..273/29 A OTHERPUBLICATIONS Tennis Rackets by F. J. Bancroft, September 1915 pages 7and 10.

The C. W. Raymond Co. Working Machinery Catalog, 1905- 1906 PrimaryExaminer-Richard C. Pinkham Assistant Examiner-Theatrice BrownAtt0rney-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT A wallstructure for practicing tennis or similar games. The structure providesa rebound surface which is non-planar so that rebound characteristicsare obtained which differ from those of a conventional flat practicewall. In particular the rebound surface defines a generally concaveconfiguration coupled with indented or projecting formations so thatgenerally a ball rebounds towards a center line of the wall but anunexpected bounce is obtained when the ball strikes a formation.

7 Claims, 11 Drawing Figures PAIENTEBHBT w 1912 same 0F 4 POL YURETHANEMAT'L.

1 NON-PLANAR BALL REBOUND WALL This invention relates broadly tosporting equipment and more particularly to a practice wall structureuseful in the practice of tennis and similar games where a ball iscontinually struck, hit or thrown by a player against such wall. Thusthe term practice wall and the phrase tennis balls and the like are tobe construed in this context. v

Hitherto a tennis player practicing alone has been limited to hittingthe ball against a substantially normal, planar smooth practice wall.While this type of practice device is adequate for the beginner, it isless useful for the more advanced player since the rebounds followreasonably expected paths and it fails to supply an element of surpriseor the need for relatively quick action on the part of the player.

It is an object of the present invention to provide a novel practicewall structure which it is believed will provide useful advantages inthe practice needs of a better than average player and which may also beused beneficially by a less experienced player.

According to the invention there is provided a practice wall structuredefining a non-planar rebound surface against which tennis balls and thelike may be projected to give rebound characteristics different fromthose of a planar wall.

Thus in one structure according to the invention the wall is curved toprovide a concave face defining at least part of the rebound surface.

In an alternative arrangement the wall includes a plurality of panelzones disposed at an angle to one another, the panel zones defining atleast part of the rebound surface.

In yet another structure according to the invention the wall ischaracterized in a general surface zone provided with formationsindented and/or in relief relative thereto, the surfaces of theformations together with the general surface zone defining the saidrebound surface.

Thus the general surface zone may be planar, the planar nature of thesurface being relieved only by the formations which operate to give thesaid different rebound characteristics.

Preferably, however, the general surface zone is concave.

Preferably also the formations provided general surface zone arepolyhedral.

It will be appreciated that with the wall arrangement characterized inthe general surface zone provided with formations as described above aball rebounding from the wall surface will move in a direction which isdependent on the zone of impact on the wall. Thus the ball will returnat relatively unexpected angles and so give a more realistic type ofreturn to the player.

Also according to the invention permanent markings on the reboundsurface representing a tennis net may be provided. Alternatively catchformations may be associated with the wall structure to secure a netadjacent thereto.

The wall may be cast in its desired shape or it may be built up ofelements such as building blocks. For this purpose, where a curved orconcave rebound surface is desired, blocks may be used which taper fromtheir rear to their front faces. Preferably such a block would taper inboth width and height so that the blocks would in the give rise to bothhorizontal and vertical curvature in the wall.

Alternatively, however, ordinary parallel sided blocks can be used andthe structure so formed that formations are built into the wall whichrelieve the surface and give the different rebound characteristics.Preferably, special blocks are utilized which themselves definenon-planar faces and together with plane sided blocks provide therequired rebound surface.

In all preferred embodiments of the wall structure however itis formedby a sheet member defining said rebound surface and preferably also thesheet is provided with a backing member and a support located betweenthe sheet and backing members. Thus the sheet may be made of a. suitablepolymer including material such as fiber glass and a space between thebacking and sheet members may be filled with a suitable material such ascellular' polyurethane to enhance the rebound of a ball projectedagainst the wall.

Further according to the invention the wall structure includes a sheetcomprising at least two sections adapted to be coupled to one another.In this way transportation of. the wall may be made easier. Furthermorethe sections may be erected at an angle to one another in effect toprovide panel zones as described above.

Preferably the structure will include at least two sections hinged oradapted to be hinged to define the said sheet. Thus, the hinge line maybe located centrally relative to the sheet or a plurality of binge linesmay be provided preferably between substantially equal sections, thehinge lines being located vertically with the structure in operativecondition. Horizontal hinge lines between panels may of course also beprovided.

The invention also includes within its ambit a court including aprepared surface, surrounding fencing and practice wall structureagainst which tennis balls and the like may be projected, characterizedin that the wall structure is one defining a rebound surface asdescribed above.

Further aspects of the invention will become clear from the followingdescription with reference to the drawings in-which:

FIG. 1 is a perspective view of one form of practice wall structure'ofthe invention;

FIG. 2 is an orthographic view of a part of thewall;

FIG. 3 is an enlarged section, partly broken away, on the line III-IIIin FIG. 2;

FIG. 4 is a further enlarged detail in perspective of a portion of thewall;

FIG. 5 is a vertical section through an alternative practice wallaccording to the invention;-

FIG. 6 is a horizontal section on the line VI-Vl in FIG. 5;

Referring to FIGS. 1 to 4 of the drawings the practice wall structure 1is approximately 18 feet long and 8 feet high and is curved in bothhorizontal and vertical directions so as to provide a general surfacezone defining non-planar rebound surface 2 which is concave. Thehorizontal radius of curvature is 29% feet long and the vertical radiusof curvature is 23 feet long. In a variation of this type of wall thelatter may be shaped in the form of portion of a sphere.

The rebound surface is broken by dished inwardly extending or indentedformations 3 located above the net line 4 of a net 5 permanently formed,as will be described hereunder, on the surface 2. The formations 3assist the action of the concave rebound surface 2 in effecting reboundcharacteristics different from those of a planar wall. In fact theformations 3 introduce an irregular rebound of a tennis ball or the likeprojected against the surface 2. However, this rebound will not be soirregular as to render practice erratic, it will merely introduce anunexpected element into the practice play.

The wall structure is formed by means of a pattern (not shown) inplaster of paris or like mouldable material shaped in any suitablefashion to the desired curve. On this curve may be placed projectingpolyhedral or pyrimidal shaped members corresponding in shape andlocation to the dished formations 3. Also a net line is defined by aprojection on the surface while the net itself is defined by a series oflateral and vertical grooves in the plaster of paris.

To form the wall 1 a fiber glass layer 6 (FIG. 4) is placed over thepattern surface and this, as shown clearly in FIGS. 1, 3 and 4, takes upthe curve and dished and relief configuration of the pattern (notshown). Thus in the fiber glass skin 6 there will be, in its concavesurface, dished polyhedral formations 3, a net line groove 4 which islater filled with a white resin material and projections 5 which definethe net.

The skin 6 is formed with rearwardly extending peripheral flanges 7against which is located a rectangular frame 8 made of rigid tubularpiping. This frame is located in position only after the tray-like skin6 has been filled with a foaming polyurethane material 9 which, when itsets to a cellular form, anchors the skin 6, frame 8 and filler 9together.

A backing 10 which may also be of fiber glass is mounted on thestructure.

As may be seen from FIG. 3 the frame 8 has rearwardly extending lugs 11on its upper side and similar lugs 12 on its lower side. When erectingthe wall structure stays 13 are pinned to the ground by their feet 13aand to the lugs 11 by suitable bolts. Also pins are inserted throughlugs 12 into the ground and the wall is then ready for use.

The wall I may be associated with its own miniature court asdiagrammatically illustrated in FIG. 11 with hardcoating 14 and fencing15 especially sized for the wall itself. Alternatively the wall I can bemounted as a border portion of a normal court.

The concave rebound surface 2 and the dish formation 3 which are about1% inches deep at their apices 3a and located above the net line give anunexpected element in the rebound of a ball and an enhanced practiceeffect. With the wall 1 it is possible for a ball to strike an outwardlydirected face 3b of a formation 3 and be deflected into the fencing 15at an angle which is too sharp to give a player much hope of effecting areturn. In order to minimize this effect, the outward faces 3b of theformations 3 are made smaller than the other faces 3c, d and e andparticularly face 3d which is directed inwardly relative to thecurvature of the wall 1.

Although the invention has been described with reference to FIGS. 1 to 4as a prefabricated wall structure it will be understood that theinvention covers a wall built in situ from blocks or the like asdescribed previously.

Thus referring to FIGS. 5 to 8 such a wall 20 is built from blocks 21and 22. The latter taper from their rear faces 22a to their front faces22b, both in their horizontal and vertical widths, and the front faces22b, are not flat but themselves define a projection. The blocks 21 areidentical to blocks 22 except that their front faces 21b are flat.

It will be realized that in erecting a wall 20 from blocks 21 and 22 avertical curve is obtained as shown in FIG. 5 due to the vertical taperof the blocks as well as a horizontal curve as shown in FIG. 6 due tothe taper in their horizontal widths. Also the special blocks 22, whichpreferably are used only above a normal tennis net line height, provideprojecting formations 22b extending from the general curved or concavefront rebound surface 20a of the wall 20. Like the indented formations 3of wall 1 these projecting formations 22b cause an unexpected bouncewhen struck by a tennis ball projected against rebound surface 20a.

Wall 20 is preferably erected on a foundation 23 and reinforcements 24may be embedded in concrete cast into the cavities 25 of the blocks tostrengthen the wall.

It is not essential to curve the practice wall structure of theinvention and in FIG. 9 there is illustrated a fiat wall 30 constructedfrom blocks 31 and 32 which correspond to blocks 21 and 22 except thatthey do not taper. Blocks 32 do, however, provide projecting formations32a so that the wall rebound surface 30a, which is defined by a planargeneral surface zone together with the surface of formations 32a, isnonplanar overall and an unexpected bounce of a ball is sometimesachieved, that is when the ball strikes a projection 32a. As shown inFIG. 9 a net 33 is suspended from hooks 34 provided on the wall 30. Itwill be appreciated that a wall structure in the form of walls 1, 20 and30 could be cast in concrete or asbestos cement or a polymer material ina suitable mould if desired.

It is also not essential to provide indented or projecting formationsrelative to a non-planar general surface zone. Thus in FIG. 10 there isillustrated a further wall 40 made, as with wall 1, from fiber glass. Inthis case the wall defines panel zones 40b, 40c, 40d and 40e which aredisposed at an angle to one another in much the same way as the faces3b,c,d and e of the dish formations 3 of wall 1 except that the panelzones are, of course, much larger and together defines the entirerebound surface 41. In other words, the rebound surface 41 is in thenature of a dished polyhedron having apex 41a.

The wall 40 is divided into three sections 42, 43 and 44 and these areconnected by hinges (not shown). Thus in transporting the wall it may befolded and when erected the sections 42, 43 and 44 can be set at anglesto one another if desired.

As stated above the practice wall structure of the invention may formpart of a miniature court as shown in FIG. 11. Although the wall 1 ishere illustrated any of the walls 20, 30 and 40 or any other wallfalling within the scope of the invention may replace such wall 1. Forexample a wall similar to 1 but excluding the formations 3 may be used.

The hardcoating 14 of such a miniature court may be specially marked asshown in FIG. 11 to enable two persons to play against the wall inaccordance with a set of rules for which the markings have beendesigned.

I claim:

1. A practice wall structure defining a rebound surface against whichplay balls may be projected, said rebound surface including a generalnon-planar surface zone having a concave shape and being curved in bothhorizontal and vertical directions, said surface zone being providedwith multi-faceted formations disposed at spaced locations in saidsurface zone, each facet of said multi-faceted formations being disposedin a plane different from said surface zone, the surfaces of saidformations together with said general surface zone defining said reboundsurface.

2. The wall structure of claim 1, wherein said multifaceted formationsare indented relative to said general surface zone.

3. The wall structure of claim 1, wherein said formations are in reliefrelative to said general surface zone.

4. The wall structure of claim 1, wherein said formations areselectively indented and in relief relative to said general surfacezone.

5. The wall structure of claim 1, wherein said multifaceted formationsare polyhedral.

6. The wall structure of claim 1, further comprising a sheet member ofpolymer material defining said rebound surface, a backing member forsaid sheet, said sheet and backing member being spaced apart from eachother, and a filler material located between said sheet and backingmembers.

7. The wall structure of claim 1, in which said sheet member includes apermanent marking thereon representing a tennis net, said reboundsurface being defined above said marking.

1. A practice wall structure defining a rebound surface against whichplay balls may be projected, said rebound surface including a generalnon-planar surface zone having a concave shape and being curved in bothhorizontal and vertical directions, said surface zone being providedwith multi-faceted formations disposed at spaced locations in saidsurface zone, each facet of said multi-faceted formations being disposedin a plane different from said surface zone, the surfaces of saidformations together with said general surface zone defining said reboundsurface.
 2. The wall stRucture of claim 1, wherein said multi-facetedformations are indented relative to said general surface zone.
 3. Thewall structure of claim 1, wherein said formations are in reliefrelative to said general surface zone.
 4. The wall structure of claim 1,wherein said formations are selectively indented and in relief relativeto said general surface zone.
 5. The wall structure of claim 1, whereinsaid multi-faceted formations are polyhedral.
 6. The wall structure ofclaim 1, further comprising a sheet member of polymer material definingsaid rebound surface, a backing member for said sheet, said sheet andbacking member being spaced apart from each other, and a filler materiallocated between said sheet and backing members.
 7. The wall structure ofclaim 1, in which said sheet member includes a permanent marking thereonrepresenting a tennis net, said rebound surface being defined above saidmarking.